I've been playing a little Dungeonmans lately. It's, sadly, a non-free, Windows-only roguelike, but it's still pretty fun. One cool feature it has is that, after you die, it examines your character, your surroundings, and the last few turns of the game, and gives you some canned advice. Things like:

* In the last turn, you took X% of your total HP in damage. Could you have reduced that somehow?
* When you died, you had X healing items in your inventory, which might have saved your life.
* Champion monsters (roughly equivalent to Angband's uniques) are very dangerous and can deal a lot more damage than usual monsters.

Some of this stuff is apparently obvious and learnable by examining the character dump, but I think it'd be helpful to newbies to highlight some things they could have done differently. An Angband-centric version of this could say things like:

* N monsters were able to see you when you died. Could you have reduced that by standing around a corner?
* You were blind/confused/stunned; these potions (that you did/did not have in your inventory) could have fixed that.
* You were paralyzed; look for items with Free Action to protect you next time.
* You had N turns below 50% health before you died. Maybe pay more attention to the low hitpoint warning next time.
* You took a lot of damage in melee. Try using Phase Door scrolls to avoid melee range, and killing dangerous enemies with wands/bows/spells instead.
* Your stats were drained. Watch out for monsters that can drain stats on touch, and try to avoid meleeing them.
* You got one-shot from full HP! Try to be more aware of dangerous enemies in your vicinity, and be very careful around monsters you haven't fought before.

Add your own!

Ideally most of these would be pretty easy to deliver by doing some very basic analysis of the current game state and the player's HP total over the last few turns. In other words, they shouldn't require invasive modifications to the game to track what was actually going on in each turn. But I think they'd be legitimately helpful for identifying some common causes of newbie deaths.

A system that I think might work would be to have an option to switch on in-game hints that are triggered by identifying a given object type. So, finding your first scroll of Phase Door shows you a tip about carrying plenty of them and phasing to escape melee. Finding your first potions of Resist Cold and Resist Fire gets you tips about how resistances work. Finding your first potion of Speed gives you a tip about the usefulness of being hasted. Etc. I think in-game tips are generally more useful and less annoying than "here's what you did wrong" after-the-fact advice. (And as Gwarl says, the "Now, how could you have done this better?" tone runs a risk of coming off as pretty patronising.)

It really depends on how it's phrased. Here, I tracked down a couple of screenshots of the Dungeonmans version:

Quote:

Eww.

I'm not thrilled by the Windows-only aspect, but there are a ton of nonfree roguelikes out there that are really worth playing. Still, I didn't intend this to be an advertisement for Dungeonmans, even though I like it a lot.